Mushrooms may soon emerge
from the dark as an unlikely but significant source
of vitamin D, the sunshine vitamin that helps keep
bones strong and fights disease.
New
research, while preliminary, suggests that brief
exposure to ultraviolet light can zap even the blandest
and whitest farmed mushrooms with a giant serving
of the vitamin. The Food and Drug Administration
proposed the study, which is being funded by industry.
Exposing
growing or just-picked mushrooms to UV light would
be cheap and easy to do if it could mean turning
the agricultural product into a unique plant source
of vitamin D, scientists and growers said. That
would be a boon especially for people who don't
eat fish or milk, which is today the major fortified
source of the important vitamin.
One
grower predicted the pilot project, if supported
by further research, could give consumers a radically
different reason to buy mushrooms, now sought out
for being low in fat and calories.
"They
eat them for what they don't have, versus what they
do have," said Joe Caldwell, vice president of Monterey
Mushrooms. The Watsonville, Calif. company is the
nation's largest producer of fresh mushrooms.
The
ongoing work so far has found that a single serving
of white button mushrooms the most commonly
sold mushroom will contain 869 percent the daily
value of vitamin D once exposed to just five minutes
of UV light after being harvested. If confirmed,
that would be more than what's in two tablespoons
of cod liver oil, one of the richest and most
detested natural sources of the vitamin, according
to the National Institutes of Health.
Details
were being presented this week at the FDA's annual
science forum. The FDA proposed the research, which
was funded by the Mushroom Council, as the agency
looks for ways to increase the amounts of vitamin
D that is consumed.
"This
could be it," said Robert Beelman, a Penn State
food scientist who's spent more than a decade working
to give mushrooms their own "nutritional identity."
Sunshine
is a significant source of vitamin D, since natural
UV rays trigger vitamin D synthesis in the skin.
Mushrooms also synthesize vitamin D, albeit in a
different form, through UV exposure. Growers typically
raise the mushrooms indoors in the dark, switching
on fluorescent lights only at harvest time. That
means they now contain negligible amounts of vitamin
D.
Research,
including new findings also being presented at the
conference, consistently has shown that many adult
Americans do not spend enough time outside to receive
enough UV exposure needed to produce ample vitamin
D. The problem is especially acute in winter.
That
worries health officials and not only because of
rickets, the soft-bone disease linked to vitamin
D deficiency that was a scourge in decades past.
Vitamin D is increasingly thought to play a role
in reducing the risk of osteoporosis, cardiovascular
disease and tooth loss, as well as in reducing mortality
associated with colon, breast, prostate and other
cancers.
Beelman
said his research has shown that exposing growing
mushrooms to three hours of artificial UV light
increases their vitamin D content significantly.
That could be easier than exposing fresh-picked
mushrooms to light, Beelman said. The only drawback
is that the white button mushrooms like people
tend to darken with increased UV exposure, he
added.
